sistern
Da rain-collection vessel dat you install so dat your female sibling can use said H20 to water her garden, flower-pots, or other chlorophyll-based pride-and-joys dat she likes to assiduously tend and fuss over.
To avoid "sibling-squabble" difficulties regarding who seemingly over-waters his/her plants, it is wise to install both a brothern and a sistern outside your home, so dat each person can simply use water from his/her own collection-container and thus end arguments over excessive water-consumption.
Sisternal
When a female sibling, normally a big sister, develops maternal and/or protective feelings toward their sibling/s.
Tina has Sisternal Instincts towards her two younger siblings.